GCN Circular 40995
Subject
GRB 250706B: iTelescope optical observations
Event
Date
2025-07-06T20:59:09Z (a day ago)
From
Filipp Dmitrievich Romanov at Amateur astronomer <filipp.romanov.27.04.1997@gmail.com>
Via
email
On 2025-07-06 I observed the field of GRB 250706B (Palmerio et al.,
GCN Circ. 40989) remotely using the telescopes T33 (0.3-m f/9
reflector + CCD with Astrodon Series II Red filter) and T17 (0.43-m
f/6.8 reflector + CMOS with Astrodon Red-E filter) of iTelescope.Net
at Siding Spring Observatory, Australia.
The exposure times of the photographs were 300 seconds, observations
started at 19:56:23 UT (2h 50m after the trigger). I detected the
optical afterglow in all images with the position (J2000.0):
02:44:55.46 -50:03:40.1.
I measured the magnitudes (compared to r' magnitudes of nearby stars
from the APASS DR9 catalog: Henden et al., 2016):
Mid-time (UT) | Magnitude | Error | Telescope |
19:58:53.3 16.852 0.073 T33
20:04:55.9 16.790 0.046 T33
20:10:58.5 16.756 0.110 T33
20:17:00.3 16.752 0.071 T33
20:05:50.8 16.738 0.040 T17
20:11:47.9 16.875 0.054 T17
20:17:43.6 16.833 0.076 T17
Magnitudes were not corrected for Galactic extinction.
F. D. Romanov (AAVSO).